Accuracy of Predicted Genomic Breeding Values in Purebred and Crossbred Pigs

Genomic selection has been widely implemented in dairy cattle breeding when the aim is to improve performance of purebred animals. In pigs, however, the final product is a crossbred animal. This may affect the efficiency of methods that are currently implemented for dairy cattle. Therefore, the objective of this study was to determine the accuracy of predicted breeding values in crossbred pigs using purebred genomic and phenotypic data. A second objective was to compare the predictive ability of SNPs when training is done in either single or multiple populations for four traits: age at first insemination (AFI); total number of piglets born (TNB); litter birth weight (LBW); and litter variation (LVR). We performed marker-based and pedigree-based predictions. Within-population predictions for the four traits ranged from 0.21 to 0.72. Multi-population prediction yielded accuracies ranging from 0.18 to 0.67. Predictions across purebred populations as well as predicting genetic merit of crossbreds from their purebred parental lines for AFI performed poorly (not significantly different from zero). In contrast, accuracies of across-population predictions and accuracies of purebred to crossbred predictions for LBW and LVR ranged from 0.08 to 0.31 and 0.11 to 0.31, respectively. Accuracy for TNB was zero for across-population prediction, whereas for purebred to crossbred prediction it ranged from 0.08 to 0.22. In general, marker-based outperformed pedigree-based prediction across populations and traits. However, in some cases pedigree-based prediction performed similarly or outperformed marker-based prediction. There was predictive ability when purebred populations were used to predict crossbred genetic merit using an additive model in the populations studied. AFI was the only exception, indicating that predictive ability depends largely on the genetic correlation between PB and CB performance, which was 0.31 for AFI. Multi-population prediction was no better than within-population prediction for the purebred validation set. Accuracy of prediction was very trait-dependent

Endoscopic full-thickness resection of T1 colorectal cancers:a retrospective analysis from a multicenter Dutch eFTR registry

Background Complete endoscopic resection and accurate histological evaluation for T1 colorectal cancer (CRC) are critical in determining subsequent treatment. Endoscopic full-thickness resection (eFTR) is a new treatment option for T1 CRC<2cm. We aimed to report clinical outcomes and short-term results. Methods Consecutive eFTR procedures for T1 CRC, prospectively recorded in our national registry between November 2015 and April 2020, were retrospectively analyzed. Primary outcomes were technical success and R0 resection. Secondary outcomes were histological risk assessment, curative resection, adverse events, and short-term outcomes. Results We included 330 procedures: 132 primary resections and 198 secondary scar resections after incomplete T1 CRC resection. Overall technical success, R0 resection, and curative resection rates were 87.0% (95% confidence interval [CI] 82.7%-90.3%), 85.6% (95%CI 81.2%-89.2%), and 60.3% (95%CI 54.7%-65.7%). Curative resection rate was 23.7% (95%CI 15.9%-33.6%) for primary resection of T1 CRC and 60.8% (95%CI 50.4%-70.4%) after excluding deep submucosal invasion as a risk factor. Risk stratification was possible in 99.3%. The severe adverse event rate was 2.2%. Additional oncological surgery was performed in 49/320 (15.3%), with residual cancer in 11/49 (22.4%). Endoscopic follow-up was available in 200/242 (82.6%), with a median of 4 months and residual cancer in 1 (0.5%) following an incomplete resection. Conclusions eFTR is relatively safe and effective for resection of small T1 CRC, both as primary and secondary treatment. eFTR can expand endoscopic treatment options for T1 CRC and could help to reduce surgical overtreatment. Future studies should focus on long-term outcomes

Transanal minimally invasive surgery (TAMIS) versus endoscopic submucosal dissection (ESD) for resection of non-pedunculated rectal lesions (TRIASSIC study):study protocol of a European multicenter randomised controlled trial

BACKGROUND: In the recent years two innovative approaches have become available for minimally invasive en bloc resections of large non-pedunculated rectal lesions (polyps and early cancers). One is Transanal Minimally Invasive Surgery (TAMIS), the other is Endoscopic Submucosal Dissection (ESD). Both techniques are standard of care, but a direct randomised comparison is lacking. The choice between either of these procedures is dependent on local expertise or availability rather than evidence-based. The European Society for Endoscopy has recommended that a comparison between ESD and local surgical resection is needed to guide decision making for the optimal approach for the removal of large rectal lesions in Western countries. The aim of this study is to directly compare both procedures in a randomised setting with regard to effectiveness, safety and perceived patient burden. METHODS: Multicenter randomised trial in 15 hospitals in the Netherlands. Patients with non-pedunculated lesions > 2 cm, where the bulk of the lesion is below 15 cm from the anal verge, will be randomised between either a TAMIS or an ESD procedure. Lesions judged to be deeply invasive by an expert panel will be excluded. The primary endpoint is the cumulative local recurrence rate at follow-up rectoscopy at 12 months. Secondary endpoints are: 1) Radical (R0-) resection rate; 2) Perceived burden and quality of life; 3) Cost effectiveness at 12 months; 4) Surgical referral rate at 12 months; 5) Complication rate; 6) Local recurrence rate at 6 months. For this non-inferiority trial, the total sample size of 198 is based on an expected local recurrence rate of 3% in the ESD group, 6% in the TAMIS group and considering a difference of less than 6% to be non-inferior. DISCUSSION: This is the first European randomised controlled trial comparing the effectiveness and safety of TAMIS and ESD for the en bloc resection of large non-pedunculated rectal lesions. This is important as the detection rate of these adenomas is expected to further increase with the introduction of colorectal screening programs throughout Europe. This study will therefore support an optimal use of healthcare resources in the future. TRIAL REGISTRATION: Netherlands Trial Register, NL7083 , 06 July 2018

Consensus-based guidance for conducting and reporting multi-analyst studies

International audienceAny large dataset can be analyzed in a number of ways, and it is possible that the use of different analysis strategies will lead to different results and conclusions. One way to assess whether the results obtained depend on the analysis strategy chosen is to employ multiple analysts and leave each of them free to follow their own approach. Here, we present consensus-based guidance for conducting and reporting such multi-analyst studies, and we discuss how broader adoption of the multi-analyst approach has the potential to strengthen the robustness of results and conclusions obtained from analyses of datasets in basic and applied research

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Cap-assisted forward-viewing endoscopy to visualize the ampulla of Vater and the duodenum in patients with familial adenomatous polyposis

Background and study aims Guidelines recommend surveillance endoscopy with both forward- and side-viewing endoscopes to identify duodenal and ampullary adenomas in patients with familial adenomatous polyposis (FAP). We hypothesized that both the duodenum and the ampulla of Vater can be completely visualized during cap-assisted forward-viewing endoscopy. Patients and methods A total of 40 patients with FAP underwent forward-viewing endoscopy with a short cap attached to the tip of the gastroscope, with the aim of visualizing both the duodenum and the ampulla of Vater. If unsuccessful, the procedure was followed by a side-viewing endoscopy. Adverse events were reported. Results The duodenum, including the ampulla of Vater, was completely visualized using the cap in 38/40 patients (95.0%). The ampulla could not be visualized using the cap in two patients, both of whom underwent additional side-viewing endoscopy, which was successful. No adverse events occurred. Conclusions This study showed that cap-assisted endoscopy can be used effectively and safely to visualize both the duodenum and the ampulla of Vater in patients with FAP. This practice might reduce burden, time, and costs of an additional side-viewing endoscop

Te veel operaties voor benigne darmpoliepen

Colorectal cancer usually starts as a benign polyp. Endoscopic removal of these polyps reduces the risk of death from colorectal cancer. Some of the colorectal polyps are seen as 'too complex for endoscopic removal' and these polyps can be surgically resected. However, surgical resection is associated with higher morbidity and mortality. We have various advanced endoscopic techniques at our disposal for removing benign polyps these days, even if they are complex. The number of surgical resections of benign polyps is nevertheless increasing in the Netherlands, partly as a result of the introduction of population screening for colorectal cancer. Only a small proportion of patients with complex polyps is referred to a centre of expertise to undergo advanced endoscopic resection. We believe that regional multidisciplinary expert panels can improve the quality of care for patients with complex polyps and reduce the number of unnecessary surgical resections

"High rate of recurrent adenomatosis during endoscopic surveillance after duodenectomy in patients with familial adenomatous polyposis"

Advanced duodenal adenomatosis in patients with familial adenomatous polyposis (FAP) is associated with a significant risk of duodenal carcinoma. Duodenectomy is sometimes indicated to prevent malignant transformation or to resect established carcinomas. Advanced recurrent adenomatosis and cancer formation in the neo-duodenum after duodenectomy in FAP have been reported. The aim of this study was to describe findings during endoscopic follow-up in a cohort of FAP patients after duodenectomy, to assess the indication and whether recommendations can be made for endoscopic surveillance. All FAP patients with a history of duodenectomy performed at a single tertiary referral centre between January 2000 and July 2011 were identified. Patient characteristics and postoperative upper endoscopic procedures were reviewed retrospectively. 19 patients, with a mean age of 49 years at the time of duodenectomy were identified. One patient was lost to follow-up. The majority of patients underwent prophylactic pancreas preserving duodenectomy (95%). Mean duration of postoperative follow-up in 18 patients was 78 months with 4 postoperative endoscopies on average. An increase in neo-Spigelman stage was seen in 9 patients, after an average interval of 35 months. Overall, newly formed adenomas in the neo-duodenum were found in 14 of 18 patients (78%), after a mean of 46 months after duodenectomy. Recurrent adenomas were mostly located in close proximity to the neo-papilla. This included advanced adenomas in 7 patients, warranting enteric re-resection in 2 patients. Continued intensive endoscopic surveillance is indicated after duodenectomy in FAP, especially of the area around the bilio- and pancreatico-enteric anastomose